The candidate's overall research program is focused on bringing detailed mechanistic knowledge of Plasmodium ookinete biology to the prevention and amelioration of human malaria. The salary support provided by a K02 award will allow Dr. Vinetz to have protected time to focus intensively on adapting advanced approaches in bioinformatics, genomics and cell biology to his ongoing, NIH-funded studies of malaria parasite biology. The candidate's immediate career goal is to attain advanced expertise in computational molecular biology and functional genomics, taking advantage of the newly established Plasmodium genome databases. This in silico expertise will be applied to systematic and comprehensive wet laboratory experimental studies of Plasmodium ookinete cell biology. The long-term goal is to achieve a detailed understanding of ookinete biology and parasite-mosquito interactions so as to develop novel strategies of preventing malaria transmission to humans. The candidate's research skills will be advanced in three ways. First, the candidate will pursue formal computational molecular biology studies (primary and comparative genome analysis, homology modeling), under the mentorship of experts in the field. Second, the candidate will gain expertise in functional genomics of Plasmodium ookinetes, in particular proteomics and DNA microarray analysis, taking advantage of state-of-the-art equipment and expertise available at the candidate's institution. Third, the candidate will learn advanced techniques in cell imaging so as to apply the bioinformatics and functional genomics skills to experiments on Plasmodium ookinetes. The Research Plan is based on two major hypotheses: that interfering with ookinete-secreted proteins, such as chitinase, will prevent parasite infection of the mosquito midgut; and that the protein trafficking machinery by which the ookinete secretes proteins extracellularly is evolutionarily conserved but differs enough from mammalian cell homologs as to provide potential drug targets to prevent mosquito midgut infection by the malaria parasite. Specific aims: 1) To develop methods of blocking malaria transmission to mosquitoes by interfering with Plasmodium chitinases and other ookinete proteins; 2) To determine mechanisms by which the targeted disruption of the carboxy terminus of the P. falciparum chitinase gene PfCHT1 prevents transmission to Anopheles mosquitoes; and 3) To delineate mechanisms by which chitinases and other proteins are secreted. These studies should provide further understanding of fundamental cell biological processes of Plasmodium ookinetes, as well as other developmental stages of Plasmodium and in other apicomplexan parasites, and help lead to alternative ways of preventing malaria.